How feasible/difficult is it to run an application that runs on a router?

Question

In my example, I want to build an application that sends users who join a network some kind of interface and manage this at a central station (possibly the router, or a central server). The new user's input to this interface will be sent back to the central station and controlled.

How plausible is this? Is sending something to a newly discovered IP realistic?

Answer 1

只要您控制DNS服务器，就可以将它们发送到您喜欢的任何Web服务器。

Answer 2

完全合理，但您需要一个带有开源固件的路由器，您需要使用该源代码的语言进行编程，并使用工具链来构建固件的二进制文件。

Answer 3

The only thing I can think of is NoCatAuth and friends. The user has to use their web browser, but most are accustomed to that.

Answer 4

Are you trying to FORCE the users to use your application (eg by selling these routers via an ISP), or are you expecting users to co-operate (eg inside a organisation's WAN)?

If the latter, it may be sufficient to set the DHCP server inside the router to serve the address of an HTTP proxy. That will get picked up by most OS/browsers. The proxy can then be used to control web-traffic - which pages they can see, and which ones are redirected to your own web-app.

If the user is considered an adversary, it would be trivial for them to override the proxy settings. In a LAN/WAN situation, you need to make sure nothing is connecting them to the outside world, except through the proxy.